Many industries today employ stand-by engine-generator systems for emergency use. One such industry is the nuclear power industry, which employs such systems for stand-by power generation. Since the stand-by engine-generators are not run on a continuous basis, the personnel assigned to maintain those systems are inexperienced when it comes to analyzing fault symptoms and determining their causes. For example, such engine-generators are often not operated for long enough periods and often enough to establish system base line operating conditions for the systems. Thus, the operators are unable to tell how far from the base line the engine's operation really is until it develops serious problems.
Manufacturers have heretofore provided the users with troubleshooting manuals, which provide "trouble indications", lists of malfunction "causes" therefor, and suggested "corrections". The difficulty presented by such publications is that one cause can result in a number of "trouble indications", thereby leaving the maintenance personnel in some confusion. Moreover, the maintenance personnel generally attempt to follow the first suggested remedy, rather than looking at all of the trouble indications and making a reasoned analysis.
This problem is especially acute in large-size diesel-generator systems which remain on stand-by for long periods of time. It is common in such engines that a single malfunction (i.e., cause) can result in a number of trouble indications. For instance, defective injection nozzles can result in high exhaust temperatures for all cylinders, an unusual change in individual cylinder exhaust temperatures, dark brown exhaust smoke, etc. Likewise, while excessive exhaust temperatures are indicative of defective injection nozzles, they may also result from incorrect injection timing, poor quality fuel oil, pyrometer error, excessive internal friction, port carbon deposits, incorrect crank lead, etc., etc. Maintenance publications are unable, in a reasonable manner, to take into account all of the combinations and permutations of possible trouble indications and causes and properly correlate them.
Accordingly, it is an object of this invention to provide a computer software system for engine trouble diagnosis, which provides a ranking of probable causes for a particular trouble indication.
It is still another object of this invention to provide a computer-based engine-diagnostic system wherein, once the diagnosis has been made from a particular indication, that the software displays other indications which ought to be observable from a determined cause.